Where do you get mockups for your projects?

Question

Design

Let's say I wrote a small service. I want to wrap it in some simple layout for beauty.
Or a library/plugin. And I want to write documentation for it on a more or less eye-pleasing page. And upload it to pages.github.com.
Where can I get the layout? Wherever you look (I googled free web templates), there are landing pages everywhere. And often some are too fancy. not suitable for service.
I tried to come up with it myself, it doesn't work very well. I don't know how to choose colors, fonts. How to style form fields, buttons. The layouts turn out to be some kind of children's. As if a schoolboy wrote in a computer science lesson.
Maybe there are special service sites for creating simple layouts that look beautiful? Prompt such.

Answer 1

Usually a designer is used for this.
If it is not at hand, then you can look for ready-made templates on the same themeforest.
Well, or take one of the hundreds of css frameworks and assemble it yourself.